Method of forming tin-containing material film and method of synthesizing a tin compound

ABSTRACT

A tin compound, tin precursor compound for atomic layer deposition (ALD), a method of forming a tin-containing material film, and a method of synthesizing a tin compound, the tin compound being represented by Chemical Formula (I): 
     
       
         
         
             
             
         
       
         
         
           
             wherein R 1 , R 2 , Q 1 , Q 2 , Q 3 , and Q 4  are each independently a C1 to C4 linear or branched alkyl group.

CROSS-REFERENCE TO RELATED APPLICATIONS

This is a divisional application based on pending application Ser. No.15/827,317, filed Nov. 30, 2017, the entire contents of which is herebyincorporated by reference.

Korean Patent Application No. 10-2016-0163900, filed on Dec. 2, 2016, inthe Korean Intellectual Property Office, and entitled: “Tin Compound,Method of Synthesizing the Same, Tin Precursor Compound for ALD, andMethod of Forming Tin-Containing Material Film,” is incorporated byreference herein in its entirety.

BACKGROUND 1. Field

Embodiments relate to a tin compound, a method of synthesizing the same,a tin precursor compound for atomic layer deposition (ALD), and a methodof forming a tin-containing material film.

2. Description of the Related Art

Due to the development of electronic technology, down-scaling ofsemiconductor devices is being quickly performed in recent years. Thus,structures of patterns constituting electronic devices may be morecomplicated and finer. Along with this, a raw material compound may becapable of forming a tin-containing thin film to a uniform thickness ona complicated and fine 3-dimensional structure by securing thermalstability upon the formation of the tin-containing thin film.

SUMMARY

Embodiments are directed to a tin compound, a method of synthesizing thesame, a tin precursor compound for atomic layer deposition (ALD), and amethod of forming a tin-containing material film.

The embodiments may be realized by providing a tin compound representedby Chemical Formula (I):

wherein R₁, R₂, Q₁, Q₂, Q₃, and Q⁴ are each independently a C1 to C4linear or branched alkyl group.

The embodiments may be realized by providing a tin precursor compoundfor atomic layer deposition (ALD), the tin precursor compound having astructure represented by Chemical Formula (I):

wherein R¹, R², Q¹, Q², Q³, and Q⁴ are each independently a C1 to C4linear or branched alkyl group.

The embodiments may be realized by providing a method of forming atin-containing material film, the method including forming a monolayerof a tin precursor compound on a substrate in a reaction space, the tinprecursor compound having a structure represented by Chemical Formula(I); forming a tin-containing material film by supplying a reactant ontothe monolayer; and removing unreacted reactant from the vicinity of asurface of the tin-containing material film by purging the unreactedreactant,

wherein R¹, R², Q¹, Q², Q³, and Q⁴ are each independently a C1 to C4linear or branched alkyl group.

The embodiments may be realized by providing a method of synthesizing atin compound, the method including obtaining SnX₂R₂ by reacting SnX₄with SnR₄ according to Reaction Formula (I); and obtaining Sn(NQ₂)₂R₂ byreacting SnX₂R₂ with LiNQ₂ according to Reaction Formula (II),

SnX₄+SnR₄→SnX₂R₂  <Reaction Formula (I)>

SnX₂R₂+2LiNQ₂→Sn(NQ₂)₂R₂+2LiX  <Reaction Formula (II)>

wherein X includes fluorine, chlorine, bromine, or iodine, and R and Qare each independently a C1 to C4 linear or branched alkyl group.

The embodiments may be realized by providing a method of forming atin-containing material film, the method including providing a substratein a reactor; supplying a tin precursor to the substrate to form amonolayer of the tin precursor, the tin precursor being represented byChemical Formula (I); supplying a reactant onto the monolayer to formthe tin-containing material film; and purging the reactor,

wherein, in Chemical Formula (I), R¹, R², Q¹, Q², Q³, and Q⁴ are eachindependently a C1 to C4 linear or branched alkyl group.

The embodiments may be realized by providing a semiconductor deviceincluding the tin-containing material film prepared by the methodaccording to an embodiment.

BRIEF DESCRIPTION OF THE DRAWINGS

Features will be apparent to those of skill in the art by describing indetail exemplary embodiments with reference to the attached drawings inwhich:

FIG. 1 illustrates a flowchart of a method of forming a tin-containingmaterial film, according to an embodiment;

FIG. 2 illustrates a timing diagram of the method of forming thetin-containing material film;

FIGS. 3A and 3B illustrate cross-sectional views of stages in a methodof forming a tin-containing material film on a substrate, according toan embodiment;

FIGS. 4A to 4H illustrate cross-sectional views of stages in a method offabricating an integrated circuit device, according to embodiments;

FIGS. 5A to 5C illustrate diagrams of an integrated circuit deviceaccording to embodiments;

FIG. 6 illustrates a graph depicting results of ¹H NMR analysis of acompound obtained in Example 1;

FIG. 7 illustrates a graph depicting results of thermal gravimetricanalysis (TGA) of the compound Sn[N(iPr)₂]₂Me₂ obtained in Example 1;

FIG. 8 illustrates a graph depicting measurement results of depositionthickness per cycle along with deposition temperature, when depositionwas performed using the compound Sn[N(iPr)₂]₂Me₂ synthesized in Example1;

FIG. 9 illustrates a transmission electron microscope (TEM) image of atin oxide thin film formed in Example 2;

FIG. 10 illustrates a graph depicting results obtained by performingX-ray diffraction (XRD) analysis on a tin oxide thin film formed inExample 2;

FIG. 11 illustrates a graph depicting results of ¹H NMR analysis of acompound obtained in Example 3;

FIG. 12 illustrates a graph depicting measurement results of depositionthickness per cycle along with deposition temperature, when depositionwas performed by using Sn[N(Me)₂]₂Me₂, synthesized in Example 3;

FIG. 13 illustrates a graph depicting measurement results of depositionthickness per cycle along with deposition temperature, when depositionwas performed by using Sn[N(Me)₂]₄, synthesized in Comparative Example1; and

FIG. 14 illustrates a graph depicting measurement results of depositionthickness per cycle along with deposition temperature, when depositionwas performed by using Sn(Me)₄.

DETAILED DESCRIPTION

Tin Compound

A tin compound according to an embodiment may be represented by ChemicalFormula (I).

In Chemical Formula (I), R¹, R², Q¹, Q², Q³, and Q⁴ may eachindependently be, e.g., a C1 to C4 linear or branched alkyl group, e.g.,a methyl group, an ethyl group, a n-propyl group, or an isopropyl group.

In an implementation, R¹ and R² in the tin compound represented byChemical Formula (I) may be the same as or different from each other. Inan implementation, Q¹, Q², Q³, and Q⁴ in the tin compound represented byChemical Formula (I) may be the same as or different from each other.

In an implementation, R¹ and R² may be the same, and Q¹, Q², Q³, and Q⁴may be the same. The following compounds are examples in which R¹ and R²are the same and Q¹, Q², Q³, and Q⁴ are the same.

In an implementation, R¹ and R² may be different, and Q¹, Q², Q³, and Q⁴may be the same. The following compounds are examples in which R¹ and R²are different and Q¹, Q², Q³, and Q⁴ are the same.

In an implementation, R¹ and R² may be the same, and not all Q¹, Q², Q³,and Q⁴ may be the same. The following compounds are examples in which R¹and R² are the same and not all Q¹, Q², Q³, and Q⁴ are the same.

In an implementation, R¹ and R² may be different, and not all Q¹, Q²,Q³, and Q⁴ may be the same. The following compounds are examples inwhich R¹ and R² are different and not all Q¹, Q², Q³, and Q⁴ are thesame.

In an implementation, R¹ and R² may be methyl groups, and all of Q¹, Q²,Q³, and Q⁴ may be isopropyl groups. In an implementation, R¹ and R² maybe methyl groups, and all of Q¹, Q², Q³, and Q⁴ may also be methylgroups. In an implementation, R¹ and R² may be ethyl groups, and all ofQ¹, Q², Q³, and Q⁴ may be isopropyl groups.

The tin compound according to embodiments may exhibit a substantiallyconstant deposition rate at a temperature of about 250° C. to about 350°C. when applied to an atomic layer deposition process. In animplementation, the tin compound may exhibit excellent long-termstorability due to high stability thereof at room temperature.

The tin compound according to an embodiment may exist in a liquid stateat room temperature, and storage and handling thereof may befacilitated. The tin compound according to an embodiment may have goodthermal stability and high reactivity, and the tin compound may form atin-containing material film with excellent step coverage when appliedto atomic layer deposition. The tin compound may not include halogenelements, and the produced tin-containing material film may not includehalogen impurities.

Method of Synthesizing Tin Compound

Hereinafter, a method of synthesizing the tin compound represented byChemical Formula (I) is described.

First, a tin halide and an alkyl compound of tin may be prepared asstarting materials and reacted with each other according to ReactionFormula (I).

SnX₄+SnR₄→2SnX₂R₂  <Reaction Formula (I)>

In Reaction Formula (I), X may include, e.g., fluorine (F), chlorine(Cl), bromine (Br), or iodine (I). The four Xs bonded to one Sn atom maybe the same or different. R may be, e.g., a C1 to C4 linear or branchedalkyl group. The four Rs bonded to one Sn atom may be the same ordifferent.

The reaction of Reaction Formula (I) may be performed, e.g., at roomtemperature or lower. In an implementation, the reaction of ReactionFormula (I) may be performed at a temperature of about 0° C. to about15° C.

SnX₂R₂, which is an intermediate product produced by the reaction ofReaction Formula (I), may be separated, followed by obtaining the tincompound represented by Chemical Formula (I) by reaction according toReaction Formula (II).

SnX₂R₂+2LiNQ₂→Sn(NQ₂)₂R₂+2LiX  <Reaction Formula (II)>

Q may be, e.g., a C1 to C4 linear or branched alkyl group. The two Qsbonded to one nitrogen (N) atom may be the same or different.

For example, the intermediate product SnX₂R₂ may be brought into contactwith a lithium amine compound substituted with a C1 to C4 linear orbranched alkyl group, thereby producing a final product Sn(NQ₂)₂R₂.

For example, when a tin compound of Sn[N(iPr)₂]₂Me₂ is intended to besynthesized, an intermediate product of Sn(CH₃)₂C1₂ may be obtained byreacting SnCl₄, which is taken as a starting material, with Sn(CH₃)₄,followed by reacting the intermediate product with lithiumdiisopropylamide (LiN(iPr)₂), thereby obtaining the desired tincompound.

For example, when a tin compound of Sn[N(Me)₂]₂Me₂ is intended to besynthesized, an intermediate product of Sn(CH₃)₂C1₂ may be obtained byreacting SnCl₄, which is taken as a starting material, with Sn(CH₃)₄,followed by reacting the intermediate product with lithium dimethylamide(LiN(Me)₂), thereby obtaining the desired tin compound.

As used herein, the abbreviation “Me” refers to a methyl group, and theabbreviation “iPr” refers to an isopropyl group. In addition, as usedherein, the terms “room temperature” and “ambient temperature” refer toa temperature ranging from about 20° C. to about 28° C., and may varywith the seasons.

In an implementation, the reaction of Reaction Formula (II) may beperformed, e.g., at a temperature of about 10° C. to about 50° C.

Formation of Tin-Containing Material Film

The tin compound described above may be used as a tin precursor compoundfor forming a tin-containing material film, e.g., a tin metal film, atin oxide film, a tin nitride film, a tin oxynitride film, or a tinoxycarbonitride film. Hereinafter, a method of forming a tin oxide filmby atomic layer deposition (ALD) will be mainly described. It will beunderstood by one of ordinary skill that a tin metal film, a tin nitridefilm, a tin oxynitride film, or a tin oxycarbonitride film may be formedby a similar method.

FIG. 1 illustrates a flowchart of a method of forming a tin-containingmaterial film, according to an embodiment. FIG. 2 illustrates a timingdiagram of the method of forming the tin-containing material film. FIGS.3A and 3B illustrate cross-sectional views of stages in the method offorming the tin-containing material film on a substrate, according to anembodiment.

Referring to FIGS. 1, 2, and 3A, a substrate 101 may be provided into areaction space, and a tin precursor compound represented by ChemicalFormula (I) may be supplied onto the substrate 101, thereby forming amonolayer 110 a of the tin precursor compound (S110).

The substrate 101 may include a semiconductor element, e.g., silicon(Si) or germanium (Ge), or a compound semiconductor, e.g., siliconcarbide (SiC), gallium arsenide (GaAs), indium arsenide (InAs), orindium phosphide (InP). In an implementation, the substrate 101 mayinclude a semiconductor substrate, and structures including at least oneinsulating film or at least one conductive region formed on thesemiconductor substrate. The at least one conductive region may include,e.g., an impurity-doped well, or an impurity-doped structure.

The forming of the monolayer 110 a by supplying the tin precursorcompound represented by Chemical Formula (I) onto the substrate 101 maybe performed while the substrate 101 is maintained at a temperature ofabout 150° C. to about 600° C. or about 250° C. to about 350° C.Maintaining the temperature of the substrate 101 at about 150° C. orgreater may help ensure that ALD reaction on the substrate 101sufficiently occurs. Maintaining the temperature of the substrate 101 atabout 600° C. or less may help ensure that ALD reaction sufficientlyoccurs by helping to prevent thermal decomposition of the tin precursorcompound.

The tin precursor compound represented by Chemical Formula (I) may besupplied onto the substrate 101 for about 1 second to about 100 seconds.Maintaining the supply time of the tin precursor compound at about 1second or greater may help ensure that the tin precursor compound isprovided at a concentration suitable for chemisorption. Maintaining thesupply time of the tin precursor compound at about 100 seconds or lessmay help ensure that the tin precursor compound is not excessivelysupplied, thus avoiding an economic disadvantage.

Although being a liquid at room temperature, the tin precursor compoundrepresented by Chemical Formula (I) may be vaporized at a relatively lowtemperature, e.g., a temperature of about 120° C. to about 180° C. Thevaporized tin precursor compound represented by Chemical Formula (I) maybe chemisorbed onto a surface of the substrate 101, thereby forming amonolayer of the tin precursor compound. In an implementation, the tinprecursor compound physisorbed onto the monolayer may further exist andmay be removed in a subsequent purge process.

Next, a purge gas may be supplied onto the surface of the substrate 101,thereby removing the unadsorbed or physisorbed tin precursor compoundrepresented by Chemical Formula (I) from the reaction space (S120). Thepurge gas may include, e.g., an inert gas such as argon (Ar), helium(He), or neon (Ne), N₂ gas, or the like.

In an implementation, as illustrated in FIG. 2, the purge gas may besupplied at the moment when the supply of the tin precursor compound isterminated. In an implementation, the purge gas may be used as a carriergas of the tin precursor compound, and the purge gas may continue to besupplied while only the supply of the tin precursor compound isterminated, thereby achieving the purge of the reaction space.

Referring to FIGS. 1, 2, and 3B, a reactant may be supplied onto thesurface of the substrate 101, thereby reacting the reactant with the tinprecursor compound represented by Chemical Formula (I), the tinprecursor compound forming the monolayer (S130). The reactant may besupplied in a vapor phase, and may be selected by taking into accountthe kind of tin-containing material film 110 to be formed on thesubstrate 101.

For example, when plasma-enhanced atomic layer deposition (PEALD) isused, plasma may be generated by applying RF power to the reactant. TheRF power may be applied to the reactant, which flows for a pulse timeperiod of the reactant, continuously flows through the reaction space,and/or flows through a remote plasma generator. Therefore, in someembodiments, the plasma may be generated in situ, and in some otherembodiments, the plasma may be remotely generated. In an implementation,the RF power applied to the reactant may range from about 10 W to about2,000 W, e.g., about 100 W to about 1,000 W or from about 200 W to about500 W. In an implementation, if allowed without damaging the substrate101, the RF power may be greater than 2,000 W.

In an implementation, when a tin oxide film is to be formed as thetin-containing material film 110, the reactant may include, e.g., O₂,O₃, plasma O₂, H₂O, NO₂, NO, N₂O (nitrous oxide), CO₂, H₂O₂, HCOOH,CH₃COOH, (CH₃CO)₂O, or mixtures thereof. In an implementation, when atin nitride film is to be formed as the tin-containing material film110, the reactant may include, e.g., NH₃, a monoalkylamine, adialkylamine, a trialkylamine, an organic amine compound, a hydrazinecompound, or mixtures thereof. In an implementation, the reactant may bea reductive gas, e.g., H₂.

When the tin-containing material film 110 includes carbon, a materialcapable of being used as a carbon precursor, which is a carbon source,may include, e.g., methane (CH₄), methanol (CH₃OH), carbon monoxide(CO), ethane (C₂H₆), ethylene (C₂H₄), ethanol (C₂H₅OH), acetylene(C₂H₂), acetone (CH₃COCH₃), propane (CH₃CH₂CH₃), propylene (C₃H₆),butane (C₄H₁₀), pentane (CH₃(CH₂)₃CH₃), pentene (C₅H₁₀), cyclopentadiene(C₅H₆), hexane (C₆H₁₄), cyclohexane (C₆H₁₂), benzene (C₆H₆), toluene(C₇H₈), or xylene (C₆H₄(CH₃)₂).

Next, the purge gas may be supplied onto the surface of the substrate101, thereby removing the unreacted reactant from the reaction space(S140). Here, by-products, which are obtained by reaction between thereactant and the tin precursor compound forming the monolayer, or thelike, may also be simultaneously removed. The purge gas may include,e.g., an inert gas such as argon (Ar), helium (He), or neon (Ne), N₂gas, or the like.

The operations described above may constitute one cycle, and may berepeated so that the tin-containing material film 110 having a desiredthickness is obtained.

To apply the tin precursor compound represented by Chemical Formula (I)to ALD, conditions in the reactor should be such that a temperaturerange allowing ALD are present. An increase rate of the thickness of thetin-containing material film per cycle may be constant in thetemperature range allowing ALD. As such, the temperature range allowingALD is referred to as an ALD window, and the ALD window may depend uponthe tin precursor compound. If the ALD window were to be too narrow, itcould be difficult to perform ALD due to a narrow process margin of anALD process. In addition, some tin compounds, e.g., those notrepresented by Chemical Formula (I), may not have the temperature rangein which the increase rate of the thickness of the tin-containingmaterial film per cycle is constant, e.g., may not have the ALD window.

At a deposition temperature out of the ALD window, the increase rate ofthe thickness of the tin-containing material film per cycle may somewhatvary depending upon the deposition temperature, despite use of the tinprecursor compound represented by Chemical Formula (I). For example, adeposition mechanism other than ALD may partially occur in deposition ofthe tin-containing material film. For example, such atemperature-dependent change of the increase rate of the thickness ofthe tin-containing material film per cycle may result from partial oroverwhelming intervention of a mechanism of chemical vapor deposition.

Formation of Tin-Containing Material Film by CVD

Although an example in which the tin-containing material film is formedby ALD has been described above, the tin precursor compound representedby Chemical Formula (I) may also be used as a precursor material forchemical vapor deposition (CVD).

For example, the tin-containing material film may be formed on asubstrate by using the tin precursor compound represented by ChemicalFormula (I). The tin precursor compound represented by Chemical Formula(I) may be in a liquid phase at room temperature and stable, and may bevaporized at a temperature of about 120° C. to about 180° C. and thusmay undergo CVD even at a relatively low temperature.

A thin film forming raw material for forming the tin-containing materialfilm may vary depending upon a thin film intended to be formed. In someembodiments, when a thin film including only tin (Sn) is fabricated, thethin film forming raw material may not include metal compounds andsemimetal compounds other than the tin precursor compound according toan embodiment. In an implementation, when a thin film including two ormore metals and/or semimetals is fabricated, the thin film forming rawmaterial may include a compound (referred to as the term “anotherprecursor” hereinafter) containing a desired metal or semimetal, inaddition to the tin precursor compound according to an embodiment. In animplementation, the thin film forming raw material may include anorganic solvent or a nucleophilic reagent in addition to the tinprecursor compound according to an embodiment.

When the thin film forming raw material is a raw material for use in aCVD process, the composition of the thin film forming raw material maybe appropriately selected depending upon a specific method of the CVDprocess, a raw material transfer method, or the like.

The raw material transfer method may include a gas transfer method and aliquid transfer method. In the gas transfer method, a raw material forCVD may be made to be in a vapor state by vaporizing the raw materialthrough heating or decompression in a container (which may be referredto as the term “raw material container” hereinafter) in which the rawmaterial is stored, and the vapor-state raw material and a carrier gassuch as argon, nitrogen, helium, or the like, which is used as needed,may be simultaneously supplied into a chamber (which may be referred toas the term “deposition reactor” hereinafter), in which the substrate isplaced, for about 1 second to about 600 seconds. In the liquid transfermethod, the raw material for CVD may be transferred in a liquid orsolution state to a vaporizer and made into vapor by vaporizing the rawmaterial through heating and/or decompression in the vaporizer, followedby introducing the vapor into the chamber. In the gas transfer method,the tin precursor compound itself represented by Chemical Formula (I)may be used as a CVD raw material. The CVD raw material may furtherinclude another precursor, a nucleophilic reagent, or the like. In animplementation, a temperature inside the chamber may be maintained atabout 100° C. to about 1,000° C. In an implementation, a pressure insidethe chamber may be maintained at about 10 Pa to about 1 atmosphere(atm).

In an implementation, in the method of forming the tin-containingmaterial film, a multi-component CVD process may be used to form thetin-containing material film. In the multi-component CVD process, amethod of supplying raw material compounds, which are to be used for theCVD process, independently for each component (hereinafter, the methodmay be referred to as the term “single source method”), or a method ofsupplying a multi-component raw material by vaporizing a raw materialmixture in which multiple components are mixed in a desired compositionratio (hereinafter, the method may be referred to as the term “cocktailsource method”) may be used. When the cocktail source method is used, afirst mixture including the tin precursor compound according to anembodiment, a first mixed solution in which the first mixture isdissolved in an organic solvent, a second mixture including the tinprecursor compound according to an embodiment and another precursor, ora second mixed solution in which the second mixture is dissolved in anorganic solvent may be used as a thin film forming raw material compoundin the CVD process. Each of the first and second mixtures and the firstand second mixed solutions may further include a nucleophilic reagent.

The organic solvent for obtaining the first or second mixed solution mayinclude, e.g., acetate esters such as ethyl acetate and methoxyethylacetate; ethers such as tetrahydrofuran, tetrahydropyran, ethyleneglycol dimethyl ether, diethylene glycol dimethyl ether, triethyleneglycol dimethyl ether, dibutyl ether, and dioxane; ketones such asmethyl butyl ketone, methyl isobutyl ketone, ethyl butyl ketone,dipropyl ketone, diisobutyl ketone, methyl amyl ketone, cyclohexanone,and methylcyclohexanone; hydrocarbons such as hexane, cyclohexane,methylcyclohexane, dimethylcyclohexane, ethylcyclohexane, heptane,octane, toluene, and xylene; cyano group-containing hydrocarbons such as1-cyanopropane, 1-cyanobutane, 1-cyanohexane, cyanocyclohexane,cyanobenzene, 1,3-dicyanopropane, 1,4-dicyanobutane, 1,6-dicyanohexane,1,4-dicyanocyclohexane, and 1,4-dicyanobenzene; pyridine; lutidine; orthe like. The organic solvents set forth above as examples may be usedalone or in combination, by taking into account solubility of a solute,temperatures for use thereof and melting points thereof, flash pointsthereof, or the like. The tin precursor compound according to anembodiment and the another precursor may be present in a totalconcentration of about 0.01 mol/L to about 2.0 mol/L, e.g., about 0.05mol/L to about 1.0 mol/L, in the organic solvent. Here, the totalconcentration of the tin precursor compound and the another precursorrefers to an amount of the tin precursor compound when the thin filmforming raw material does not include metal compounds and semimetalcompounds other than the tin precursor compound, and refers to a sum ofamounts of the tin precursor compound and the another precursor when thethin film forming raw material further includes, in addition to the tinprecursor compound, a compound containing other metals than tin or acompound containing semimetals.

In an implementation, examples of the other precursor in the method offorming the thin film may include at least one Si or metal compoundselected from among compounds having hydride, hydroxide, halide, azide,alkyl, alkenyl, cycloalkyl, allyl, alkynyl, amino, dialkylaminoalkyl,monoalkylamino, dialkylamino, diamino, di(silyl-alkyl)amino,di(alkyl-silyl)amino, disilylamino, alkoxy, alkoxyalkyl, hydrazide,phosphide, nitrile, dialkylaminoalkoxy, alkoxyalkyldialkylamino, siloxy,diketonate, cyclopentadienyl, silyl, pyrazolate, guanidinate,phosphoguanidinate, amidinate, ketoiminate, diketoiminate, carbonyl, andphosphoamidinate groups as ligands.

In an implementation, the metal included in the other precursor mayinclude, e.g., magnesium (Mg), calcium (Ca), strontium (Sr), barium(Ba), radium (Ra), scandium (Sc), yttrium (Y), titanium (Ti), zirconium(Zr), hafnium (Hf), vanadium (V), niobium (Nb), chromium (Cr),molybdenum (Mo), tungsten (W), manganese (Mn), iron (Fe), osmium (Os),cobalt (Co), rhodium (Rh), iridium (Ir), nickel (Ni), palladium (Pd),platinum (Pt), copper (Cu), silver (Ag), gold (Au), zinc (Zn), cadmium(Cd), aluminum (Al), gallium (Ga), indium (In), germanium (Ge), tantalum(Ta), lead (Pb), antimony (Sb), bismuth (Bi), lanthanum (La), cerium(Ce), praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium (Sm),europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium(Ho), erbium (Er), thulium (Tm), ytterbium (Yb), or the like.

In an implementation, when an alcohol compound is used as an organicligand, the other precursor may be prepared by reacting an inorganicsalt of the metal set forth above or a hydrate thereof with an alkalimetal alkoxide of the alcohol compound. In an implementation, examplesof the inorganic salt of the metal or the hydrate thereof may includehalides, nitrates, and the like of the metal, and examples of the alkalimetal alkoxide may include sodium alkoxides, lithium alkoxides,potassium alkoxides, and the like.

In the single source method, as the other precursor, a compoundexhibiting thermal and/or oxidative decomposition behaviors that aresimilar to those of the tin precursor compound according to anembodiment may be used. In addition, in the cocktail source method, itis suitable to use, as the other precursor, a compound that exhibitsthermal and/or oxidative decomposition behaviors similar to those of thetin precursor compound and is not altered by chemical reactions or thelike upon mixing thereof.

Application of Tin-Containing Material Film

The tin-containing material film fabricated by the method of forming thethin film, may be used for various purposes. For example, thetin-containing material film may be used for a gate of a transistor, aconductive barrier film included in a metal wire such as a copper wire,a tunnel barrier film of a gate dielectric film included in a3-dimensional charge trap flash (CTF) cell, a barrier metal film forliquid crystals, a member for thin film solar cells, a member forsemiconductor equipment, a nano-structure, or the like.

FIGS. 4A to 4H illustrate cross-sectional views of stages in a method offabricating an integrated circuit device, according to embodiments. Amethod of fabricating a memory cell array of an integrated circuitdevice 200 (see FIG. 4H) constituting a vertical non-volatile memorydevice will be described with reference to FIGS. 4A to 4H.

Referring to FIG. 4A, an etch stop insulating film 222 may be formed ona substrate 210, and a plurality of sacrificial layers P224 and aplurality of insulating layers 226 may be alternately stacked on theetch stop insulating film 222, layer by layer. A thickness of theuppermost insulating layer 226 may be greater than a thickness ofanother insulating layer 226.

The substrate 210 may be the same as the substrate 101 described above,and repeated descriptions thereof may be omitted.

The etch stop insulating film 222 and the plurality of insulating layers226 may include an insulating material, e.g., silicon oxide. Theplurality of sacrificial layers P224 may include a material having etchselectivity that is different from those of the etch stop insulatingfilm 222 and the plurality of insulating layers 226. For example, theplurality of sacrificial layers P224 may include a silicon nitride film,a silicon oxynitride film, a polysilicon film, or a polysilicongermanium film.

Referring to FIG. 4B, a plurality of channel holes 230 may be formedthrough the plurality of insulating layers 226, the plurality ofsacrificial layers P224, and the etch stop insulating film 222 and mayexpose the substrate 210.

Referring to FIG. 4C, a charge storage film 232 and a tunnel dielectricfilm 234 may be formed in this stated order and cover an inner wall ofeach of the plurality of channel holes 230, and a channel region 240 maybe formed and covers the tunnel dielectric film 234.

For example, the charge storage film 232 and the tunnel dielectric film234 may be formed in the plurality of channel holes 230. Next, a channelregion-forming semiconductor film may be formed on the tunnel dielectricfilm 234 in the plurality of channel holes 230, followed byanisotropically etching the semiconductor film, thereby exposing thesubstrate 210 in each of the plurality of channel holes 230. Thesemiconductor film may remain as the spacer-shaped channel region 240,which covers a sidewall of the tunnel dielectric film 234 in each of theplurality of channel holes 230. In an implementation, the charge storagefilm 232 may include a silicon nitride film. The tunnel dielectric film234 may include a silicon oxide film.

The channel region 240 may not completely fill an inside of each channelhole 230. An insulating film 242 may fill a space remaining above thechannel region 240 in each channel hole 230.

Next, the charge storage film 232, the tunnel dielectric film 234, thechannel region 240, and the insulating film 242 in the plurality ofchannel holes 230 may be partially removed, whereby an upper space maybe formed in each of the plurality of channel holes 230, and aconductive pattern 250 may fill the upper space. The conductive pattern250 may include doped polysilicon or a metal. The conductive pattern 250may be used as a drain region.

Referring to FIG. 4D, a plurality of openings 260 may be formed throughthe plurality of insulating layers 226, the plurality of sacrificiallayers P224, and the etch stop insulating film 222 and may expose thesubstrate 210. Each of the plurality of openings 260 may be a word linecut region.

Referring to FIG. 4E, the plurality of sacrificial layers P224 may beremoved from the plurality of openings 260, thereby forming a pluralityof gate spaces GS each between two of the plurality of insulating layers226. The charge storage film 232 may be exposed by the plurality of gatespaces GS.

Referring to FIG. 4F, a blocking insulating film 236 may be formed andmay cover inner walls of the plurality of gate spaces GS.

The blocking insulating film 236 may include a tin oxide film. To formthe blocking insulating film 236, the method of forming the thin filmmay be used, the method having been described with reference to FIGS. 1to 3B. In an implementation, to form the blocking insulating film 236,an ALD process may be used. As a Sn source, the tin precursor compoundaccording to an embodiment, e.g., the tin precursor compound representedby Chemical Formula (I), may be supplied through the plurality ofopenings 260. The ALD process may be performed at a first temperatureselected from a range of about 250° C. to about 350° C. After theformation of the tin oxide film, the tin oxide film may be densified byannealing the tin oxide film at a second temperature that is higher thanthe first temperature. The second temperature may be selected from arange of about 400° C. to about 1,150° C.

Referring to FIG. 4G, a conductive layer for gate electrodes may beformed and may fill spaces surrounded by the blocking insulating film236 and remaining in the plurality of gate spaces GS, followed bypartially removing the blocking insulating film 236 and the conductivelayer for gate electrodes so that a sidewall of each of the plurality ofinsulating layers 226 in the plurality of openings 260 is exposed,whereby the blocking insulating film 236 and a gate electrode 264 remainin the plurality of openings 260.

In an implementation, the gate electrode 264 may include a firstconductive barrier film contacting the blocking insulating film 236, anda first conductive film on the first conductive barrier film. The firstconductive barrier film may include a conductive metal nitride, e.g.,TiN or TaN. The first conductive film may include conductivepolysilicon, a metal, a metal silicide, or combinations thereof.

The blocking insulating film 236 may include a tin oxide film free fromundesired foreign substances such as halogen materials or carbonresidue. As described with reference to FIG. 4F, the tin oxide film maybe annealed and thus densified, thereby preventing, e.g., damage of aconstitution material of the gate electrode 264 filling the gate spacesGS since an excess of the blocking insulating film 236 may be consumedby an etching solution or the blocking insulating film 236 at entrancesides of the plurality of gate spaces GS undergoes undesired removal byan etching solution, while the blocking insulating film 236 and theconductive layer for gate electrodes are partially removed in theprocess of FIG. 4G so that the sidewall of each of the plurality ofinsulating layers 226 may be exposed.

As described above, after the blocking insulating film 236 and the gateelectrode 264 are formed in the plurality of gate spaces GS, thesubstrate 210 may be exposed by the plurality of openings 260. Aplurality of common source regions 268 may be formed in the substrate210 by implanting impurities into the substrate 210 exposed by theplurality of openings 260.

Referring to FIG. 4H, an insulating spacer 272 may be formed on an innersidewall of each of the plurality of openings 260, and a conductive plug274 may fill an inner space of each of the plurality of openings 260.

In an implementation, the insulating spacer 272 may include a siliconoxide film, a silicon nitride film, or combinations thereof. Theconductive plug 274 may include a second conductive barrier filmcontacting the insulating spacer 272, and a second conductive filmfilling a space surrounded by the second conductive barrier film in eachof the plurality of openings 260. The second conductive barrier film mayinclude a conductive metal nitride, e.g., TiN or TaN. The secondconductive film may include a metal, e.g., tungsten.

A plurality of first contacts 282 may be respectively formed on aplurality of conductive plugs 274, and a plurality of first conductivelayers 284 may be respectively formed on the plurality of first contacts282. Each of the plurality of first contacts 282 and the plurality offirst conductive layers 284 may include a metal, a metal nitride, orcombinations thereof.

A plurality of second contacts 292 and a plurality of bit lines 294 maybe formed on a plurality of conductive patterns 250. Each of theplurality of second contacts 292 and the plurality of bit lines 294 mayinclude a metal, a metal nitride, or combinations thereof.

According to the method of fabricating the integrated circuit device200, which has been described with reference to FIGS. 4A to 4H, the tinprecursor compound according to an embodiment may be used in the ALDprocess for forming the blocking insulating film 236 including tinoxide, thereby securing properties required as a raw material compoundupon the ALD process, e.g., high thermal stability, low melting point,high vapor pressure, transportability in a liquid state, ease ofvaporization, and the like. Therefore, the blocking insulating film 236may be easily formed by using the tin precursor compound according to anembodiment. In addition, the blocking insulating film 236 having uniformstep coverage along the depths of holes having relatively high aspectratios may be obtained.

FIGS. 5A to 5C illustrate an integrated circuit device according toembodiments. FIG. 5A illustrates perspective views of main components ofan integrated circuit device 500 including a first transistor TR51 and asecond transistor TR52, which have FinFET structures, FIG. 5Billustrates cross-sectional views respectively taken along lines B1-B1′and B2-B2′ of FIG. 5A, and FIG. 5C illustrates cross-sectional viewsrespectively taken along lines C1-C1′ and C2-C2′ of FIG. 5A.

The integrated circuit device 500 may include a first fin-type activeregion F1 and a second fin-type active region F2, which respectivelyprotrude from a first region I and a second region II of a substrate 510in a direction (Z direction) perpendicular to a main surface of thesubstrate 510.

The first region I and the second region II refer to different regionsof the substrate 510 and may be regions performing different functionson the substrate 510. The first transistor TR51 and the secondtransistor TR52, which require different threshold voltages, may berespectively formed in the first region I and the second region II. Inan implementation, the first region I may be a PMOS transistor region,and the second region II may be an NMOS transistor region.

The first fin-type active region F1 and the second fin-type activeregion F2 may extend along one direction (Y direction in FIGS. 5A to5C). In the first region I and the second region II, a first deviceisolation film 512 and a second device isolation film 514 may be formedon the substrate 510 and may respectively cover lower sidewalls of thefirst fin-type active region F1 and the second fin-type active regionF2. The first fin-type active region F1 may protrude in a fin shapeupwards from the first device isolation film 512, and the secondfin-type active region F2 may protrude in a fin shape upwards from thesecond device isolation film 514.

The first fin-type active region F1 and the second fin-type activeregion F2 may respectively have a first channel region CH1 and a secondchannel region CH2 on upper portions thereof. A P-type channel may beformed in the first channel region CH1, and an N-type channel may beformed in the second channel region CH2.

In an implementation, each of the first fin-type active region F1 andthe second fin-type active region F2 may include a single material. Forexample, the first fin-type active region F1 and the second fin-typeactive region F2, which respectively include the first channel regionCH1 and the second channel region CH2, may include Si in all regionsthereof. In an implementation, the first fin-type active region F1 andthe second fin-type active region F2 may respectively include a regionincluding Ge and a region including Si.

Each of the first and second device isolation films 512 and 514 mayinclude a silicon-containing insulating film, e.g., a silicon oxidefilm, a silicon nitride film, a silicon oxynitride film, a siliconcarbonitride film, or the like, polysilicon, or combinations thereof.

In the first region I, a first gate structure GA may extend on the firstfin-type active region F1 in a direction (X direction in FIGS. 5A to 5C)intersecting the extension direction of the first fin-type active regionF1, the first gate structure GA including a first interfacial film 522A,a first high-K dielectric film 524A, a first etch stop layer 526A, afirst work function adjusting layer 528, a second work functionadjusting layer 529, and a first gap-fill gate film 530A, which arestacked in this stated order. The first transistor TR51 may be formed ata point at which the first fin-type active region F1 intersects thefirst gate structure GA.

In the second region II, a second gate structure GB extends on thesecond fin-type active region F2 in the direction (X direction in FIGS.5A to 5C) intersecting the extension direction of the second fin-typeactive region F2, the second gate structure GB including a secondinterfacial film 522B, a second high-K dielectric film 524B, a secondetch stop layer 526B, the second work function adjusting layer 529, anda second gap-fill gate film 530B, which are stacked in this statedorder. The second transistor TR52 may be formed at a point at which thesecond fin-type active region F2 intersects the second gate structureGB.

The first interfacial film 522A and the second interfacial film 522B mayinclude films obtained by oxidizing surfaces of the first fin-typeactive region F1 and the second fin-type active region F2, respectively.In an implementation, each of the first interfacial film 522A and thesecond interfacial film 522B may include a low-K dielectric materiallayer having a dielectric constant of about 9 or less, e.g., a siliconoxide film, a silicon oxynitride film, or combinations thereof. In animplementation, each of the first interfacial film 522A and the secondinterfacial film 522B may have a thickness of, e.g., about 5 Å to about20 Å. In an implementation, the first interfacial film 522A and thesecond interfacial film 522B may be omitted.

Each of the first high-K dielectric film 524A and the second high-Kdielectric film 524B may include a metal oxide having a higherdielectric constant than a silicon oxide film. For example, each of thefirst high-K dielectric film 524A and the second high-K dielectric film524B may have a dielectric constant of about 10 to about 25. In animplementation, each of the first high-K dielectric film 524A and thesecond high-K dielectric film 524B may include, e.g., hafnium oxide,hafnium oxynitride, hafnium silicon oxide, lanthanum oxide, lanthanumaluminum oxide, zirconium oxide, zirconium silicon oxide, tin oxide, tinoxynitride, tin oxycarbonitride, tantalum oxide, titanium oxide, bariumstrontium titanium oxide, barium titanium oxide, strontium titaniumoxide, yttrium oxide, aluminum oxide, lead scandium tantalum oxide, leadzinc niobate, or combinations thereof.

The first high-K dielectric film 524A and the second high-K dielectricfilm 524B may be formed by an ALD or CVD process. In an implementation,each of the first high-K dielectric film 524A and the second high-Kdielectric film 524B may have a thickness of, e.g., about 10 Å to about40 Å.

When each of the first high-K dielectric film 524A and the second high-Kdielectric film 524B includes a Sn-containing film, the first high-Kdielectric film 524A and the second high-K dielectric film 524B may beformed by using a thin film forming raw material, which includes the tinprecursor compound represented by Chemical Formula (I) as set forthabove.

Each of the first etch stop layer 526A and the second etch stop layer526B may include a SnN film. The first etch stop layer 526A and thesecond etch stop layer 526B may be formed by a CVD or ALD process byusing a thin film forming raw material, which includes the tin precursorcompound represented by Chemical Formula (I) as set forth above, andusing a nitrogen atom-containing reactive gas, for example, NH₃ gas.

The first work function adjusting layer 528 may be for adjusting a workfunction of the P-type transistor, and may include, e.g., TiN.

The second work function adjusting layer 529 may be for adjusting a workfunction of the N-type transistor, and may include, e.g., TiAl, TiAlC,TiAlN, TaC, TiC, HfSi. or combinations thereof.

Each of the first gap-fill gate film 530A and the second gap-fill gatefilm 530B may include, e.g., tungsten (W).

In an implementation, a conductive barrier film may be interposedbetween the second work function adjusting layer 529 and the firstgap-fill gate film 530A, and/or between the second work functionadjusting layer 529 and the second gap-fill gate film 530B. In animplementation, the conductive barrier film may include a metal nitride,e.g., TiN, TaN, SnN, or combinations thereof.

A pair of first source/drain regions 562 may be formed in the firstfin-type active region F1 at both sides of the first gate structure GA.A pair of second source/drain regions 564 may be foamed in the secondfin-type active region F2 at both sides of the second gate structure GB.

The pairs of first and second source/drain regions 562 and 564 mayrespectively include semiconductor layers epitaxially grown on the firstand second fin-type active regions F1 and F2. Each of the pairs of firstand second source/drain regions 562 and 564 may include an embedded SiGestructure including a plurality of epitaxially grown SiGe layers, anepitaxially grown Si layer, or an epitaxially grown SiC layer.

In an implementation, as illustrated in FIGS. 5A and 5C, the pairs offirst and second source/drain regions 562 and 564 may have a specificshape. In an implementation, the pairs of first and second source/drainregions 562 and 564 may have various sectional shapes.

Each of the first and second transistors TR51 and TR52 may include a3-dimensional structured MOS transistor in which a channel is formed onan upper surface and both side surfaces of each of the first and secondfin-type active regions F1 and F2. The MOS transistor may constitute anNMOS transistor or a PMOS transistor.

In the first region I and the second region II, an insulating spacer 572may be formed on both sides of each of the first and second gatestructures GA and GB. As shown in FIG. 5C, an insulating film 578covering the insulating spacer 572 may be formed at an opposite side toeach of the first and second gate structures GA and GB, with theinsulating spacer 572 being between each of the first and second gatestructures GA and GB and the insulating film 578. In an implementation,the insulating spacer 572 may include a silicon nitride film and theinsulating film 578 may include a silicon oxide film.

The following Examples and Comparative Examples are provided in order tohighlight characteristics of one or more embodiments, but it will beunderstood that the Examples and Comparative Examples are not to beconstrued as limiting the scope of the embodiments, nor are theComparative Examples to be construed as being outside the scope of theembodiments. Further, it will be understood that the embodiments are notlimited to the particular details described in the Examples andComparative Examples.

Example 1

Synthesis of Compound Sn[N(iPr)₂]₂Me₂

100 g (0.35 mol) of SnCl₄ and 300 ml of n-hexane were introduced into a1,000 ml flask and mixed. 81.4 g (0.455 mol) of Sn(Me)₄ was slowly addedinto the flask in an ice bath. The components were stirred for about 2hours, thereby completing synthesis of SnMe₂Cl₂.

Next, 204 g (1.91 mol) of lithium diisopropylamide (LDA) was dilutedwith ethyl ether and then slowly added into the flask. The reaction wascompleted by stirring the components for 5 hours, followed by removing asolvent and by-products at reduced pressure.

Next, the resultant was purified at a temperature of 80° C. and apressure of 0.6 Torr, thereby obtaining 120 g of a compoundSn[N(iPr)₂]₂Me₂ (yield: 77%).

The obtained compound underwent ¹H NMR analysis. Results are shown inFIG. 6.

(Analysis)

¹H NMR (C6D6): δ 3.42 (st, 4H), 1.12 (d, 24H), 0.38 (s, 6H)

Evaluation Example 1

Evaluation of Properties of Compound Sn[N(iPr)₂]₂Me₂

FIG. 7 illustrates a graph depicting results of thermal gravimetricanalysis (TGA) of the compound Sn[N(iPr)₂]₂Me₂ obtained in Example 1. 10mg of the compound Sn[N(iPr)₂]₂Me₂ was analyzed at a heating rate of 10°C./min under an argon atmosphere.

FIG. 7 shows weight loss percentage along with temperature. As may beseen in FIG. 7, the Sn[N(iPr)₂]₂Me₂ exhibited quick vaporization and wasvaporized to a degree of 99% or more at about 190° C. without residuedue to thermal decomposition.

Example 2

A tin oxide thin film was fabricated on a silicon substrate by atomiclayer deposition (ALD).

The silicon substrate was loaded into a reaction chamber and maintainedat a temperature of 200° C. The compound Sn[N(iPr)₂]₂Me₂ synthesized inExample 1 filled a stainless steel bubbler container and was maintainedat a temperature of 74° C. Next, the tin precursor compound wasvaporized in the bubbler container and supplied onto a surface of thesilicon substrate using argon gas as a carrier gas (25 sccm), therebychemisorbing the compound Sn[N(iPr)₂]₂Me₂ onto the silicon substrate.Next, unadsorbed Sn[N(iPr)₂]₂Me₂ was purged with argon gas (4,000 sccm)for 15 seconds and thereby removed from the reaction chamber.

Next, ozone gas having a concentration of 220 g/m³ was supplied into thereaction chamber at a flow rate of 300 sccm for 7 seconds, therebyforming the tin oxide thin film. Finally, by-products and unreactedmaterials were purged with argon gas (4,000 sccm) for 10 seconds andthereby removed from the reaction chamber.

When the processes set forth above were defined as 1 cycle, a tin oxidethin film was formed by repeating 100 cycles and underwent thicknessmeasurement.

In addition, deposition for 100 cycles was performed at each temperaturewhile changing the temperature inside the reaction chamber, and adeposition thickness per cycle at each temperature was measured. Resultsare shown in FIG. 8.

As shown in FIG. 8, it may be seen that the deposition thickness percycle changed along with the deposition temperature varying from 200° C.to 270° C. Therefore, it may be seen that a deposition mechanism otherthan ALD could contributed to the formation of the thin film at 200° C.to 270° C. Likewise, it may be seen that the deposition thickness percycle changed along with the deposition temperature varying from 350° C.to 380° C. Therefore, it may be seen that a deposition mechanism otherthan ALD, e.g., chemical vapor deposition, may have contributed to theformation of the thin film at 350° C. to 380° C.

It may be seen that the deposition thickness per cycle was constant evenwhen the deposition temperature varied in a range of 270° C. to 350° C.For example, in a temperature range of 270° C. to 350° C., the tin oxidethin film was formed by a mechanism of ALD.

To analyze a crystal structure of the tin oxide thin film formed asabove, transmission electron microscope (TEM) analysis and X-raydiffraction (XRD) analysis were performed on the tin oxide thin film,and an image obtained by analysis and a graph of analysis results arerespectively shown in FIGS. 9 and 10.

Referring to FIG. 9, it may be seen that the tin oxide (SnO₂) thin filmwas formed on the silicon substrate and a glue layer for TEM analysiswas formed on the tin oxide thin film. As shown in FIG. 9, it may beseen that the tin oxide thin film was formed to a relatively uniformthickness on the silicon substrate.

The composition of the tin oxide thin film was analyzed by X-rayphotoelectron spectroscopy (XPS), and results thereof are shown inTable 1. Referring to Table 1, it may be seen that the deposited thinfilm included about 33.3 atom % of tin and about 66.7 atom % of oxygenbased on a silicon substrate temperature of 300° C., and astoichiometric ratio of tin to oxygen was about 1:2. Thus, the thin filmhad a composition of SnO₂. In addition, nitrogen, carbon, and halogenelements, which were impurities, were not detected, and it may be seenthat the pure tin oxide thin film free from impurities was formed.

TABLE 1 Temperature Atom % (XPS) (° C.) Sn 3d O 1s N 1s C 1s O/Sn 27032.6 67.4 0.0 0.0 2.1 300 33.3 66.7 0.0 0.0 2.0 340 32.0 68.0 0.0 0.02.1 350 32.6 67.4 0.0 0.0 2.1

Referring to FIG. 10, it may be seen that, at a 2-theta (0) value of 26degree (°) where peaks exist, the intensity of the peak representing arutile phase increased with increasing deposition temperature. Forexample, crystallinity of the rutile phase was observed at 300° C., andit may be seen that the crystallinity increased with increasingtemperature. In addition, the crystallinity could also be confirmed bythe TEM image shown in FIG. 9.

Example 3

Synthesis of Compound Sn[N(Me)₂]₂Me₂

117 g (0.45 mol) of SnCl₄ and 300 ml of n-hexane were introduced into a1,000 ml flask and mixed. 81.4 g (0.455 mol) of Sn(Me)₄ was slowly addedinto the flask in an ice bath. The components were stirred for about 2hours, thereby completing synthesis of SnMe₂Cl₂.

Next, 101 g (1.98 mol) of lithium dimethylamide (Li-DMA) was dilutedwith ethyl ether and then slowly added into the flask. The reaction wascompleted by stirring the components for 5 hours, followed by removing asolvent and by-products at reduced pressure.

Next, the resultant was purified at a temperature of 80° C. and apressure of 0.6 Torr, thereby obtaining 120 g of a compoundSn[N(Me)₂]₂Me₂ (yield: 56%).

The obtained compound underwent ¹H NMR analysis. The results are shownin FIG. 11.

(Analysis)

¹H NMR (C6D6): δ 2.76 (s, 12H), 0.09 (s, 6H)

Example 4

A tin oxide thin film was formed in the same manner as in Example 2except that the compound Sn[N(Me)₂]₂Me₂ was used instead of the compoundSn[N(iPr)₂]₂Me₂, and a deposition thickness of tin oxide per cycle wasmeasured at each deposition temperature. Results are shown in FIG. 12.

As shown in FIG. 12, it may be seen that the deposition thickness percycle changed along with the deposition temperature varying from 200° C.to 270° C. Therefore, it may be seen that a deposition mechanism otherthan ALD could have contributed to the formation of the thin film at200° C. to 270° C. Likewise, it may be seen that the depositionthickness per cycle changed along with the deposition temperaturevarying from 320° C. to 400° C. Therefore, it may be seen that adeposition mechanism other than ALD, e.g., chemical vapor deposition,could have contributed to the formation of the thin film at 320° C. to400° C.

It may be seen that the deposition thickness per cycle was constant evenwhen the deposition temperature varied in a range of 270° C. to 320° C.For example, in a temperature range of 270° C. to 320° C., the tin oxidethin film was formed by a mechanism of ALD.

Comparative Example 1

Synthesis of Compound Sn[N(Me)₂]₄

100 g (0.35 mol) of SnCl₄ and 300 ml of n-hexane were introduced into a1,000 ml flask and mixed. 80 g (1.57 mol) of lithium dimethylamide(Li-DMA) was diluted with ethyl ether and then slowly added into theflask in an ice bath, followed by stirring the components at ambienttemperature for 8 hours, thereby completing the reaction. Aftercompleting the reaction, LiCl salts were removed by filtering theproduct, thereby obtaining a solution. Next, a solvent and by-productswere removed from the obtained solution at reduced pressure. After theremoval of the solvent, the solution was purified, thereby obtaining 63g of a compound Sn[N(Me)₂]₄ (yield: 70%).

(Analysis)

¹H NMR (C6D6): δ 2.79 (s, 24H)

Formation of Tin Oxide Thin Film

A tin oxide thin film was formed in the same manner as in Example 2except that the compound Sn[N(Me)₂]₄ was used instead of the compoundSn[N(iPr)₂]₂Me₂, and a deposition thickness of tin oxide per cycle wasmeasured at each deposition temperature. Results are shown in FIG. 13.

As shown in FIG. 13, the deposition thickness per cycle decreased alongwith the deposition temperature varying from 100° C. to 150° C., and thedeposition thickness per cycle increased along with the depositiontemperature increasing from 150° C. to 400° C. For example, atemperature range, in which the deposition thickness per cycle wasconstant, was not observed. This means that a range allowing depositionby a mechanism of ALD to be dominant was not present throughout thewhole temperature range when the compound Sn[N(Me)₂]₄ was used.Therefore, the compound Sn[N(Me)₂]₄ may be unsuitable as an ALDprecursor.

When the compound Sn[N(Me)₂]₄ is used, there may be no temperature rangeallowing deposition by the mechanism of ALD to be dominant, and mostdeposition may be presumed to be performed by a mechanism of CVD.Therefore, it may be difficult to form a thin film with excellent stepcoverage on a surface of a structure having a high aspect ratio.

Comparative Example 2

A tin oxide thin film was formed in the same manner as in Example 2except that Sn(Me)₄ was used instead of the Sn[N(iPr)₂]₂Me₂, and adeposition thickness of tin oxide per cycle was measured at eachdeposition temperature. Results are shown in FIG. 14. The Sn(Me)₄ was acommercially available product (Sigma-Aldrich Co., Ltd.), which had a95% grade.

As shown in FIG. 14, the deposition thickness per cycle increased alongwith the deposition temperature varying from 250° C. to 350° C. Forexample, a temperature range, in which the deposition thickness percycle was constant, was not observed. This means that a range allowingdeposition by the mechanism of ALD to be dominant was not presentthroughout the whole temperature range. Therefore, the Sn(Me)₄ may beunsuitable as an ALD precursor.

When Sn(Me)₄ was used, there was no temperature range allowingdeposition by the mechanism of ALD to be dominant, and most depositionwas presumed to be performed by the mechanism of CVD. Therefore, it maybe difficult to form a thin film with excellent step coverage on asurface of a structure having a high aspect ratio.

As is traditional in the field, embodiments are described, andillustrated in the drawings, in terms of functional blocks, units and/ormodules. Those skilled in the art will appreciate that these blocks,units and/or modules are physically implemented by electronic (oroptical) circuits such as logic circuits, discrete components,microprocessors, hard-wired circuits, memory elements, wiringconnections, and the like, which may be formed using semiconductor-basedfabrication techniques or other manufacturing technologies. In the caseof the blocks, units and/or modules being implemented by microprocessorsor similar, they may be programmed using software (e.g., microcode) toperform various functions discussed herein and may optionally be drivenby firmware and/or software. Alternatively, each block, unit and/ormodule may be implemented by dedicated hardware, or as a combination ofdedicated hardware to perform some functions and a processor (e.g., oneor more programmed microprocessors and associated circuitry) to performother functions. Also, each block, unit and/or module of the embodimentsmay be physically separated into two or more interacting and discreteblocks, units and/or modules without departing from the scope herein.Further, the blocks, units and/or modules of the embodiments may bephysically combined into more complex blocks, units and/or moduleswithout departing from the scope herein.

Example embodiments have been disclosed herein, and although specificterms are employed, they are used and are to be interpreted in a genericand descriptive sense only and not for purpose of limitation. In someinstances, as would be apparent to one of ordinary skill in the art asof the filing of the present application, features, characteristics,and/or elements described in connection with a particular embodiment maybe used singly or in combination with features, characteristics, and/orelements described in connection with other embodiments unless otherwisespecifically indicated. Accordingly, it will be understood by those ofskill in the art that various changes in form and details may be madewithout departing from the spirit and scope of the present invention asset forth in the following claims.

1.-10. (canceled)
 11. A method of forming a tin-containing materialfilm, the method comprising: forming a monolayer of a tin precursorcompound on a substrate in a reaction space, the tin precursor compoundhaving a structure represented by Chemical Formula (I); forming atin-containing material film by supplying a reactant onto the monolayer;and removing unreacted reactant from the vicinity of a surface of thetin-containing material film by purging the unreacted reactant,

wherein R¹, R², Q¹, Q², Q³, and Q⁴ are each independently a C1 to C4linear or branched alkyl group.
 12. The method as claimed in claim 11,wherein: the reactant includes O₂, O₃, plasma O₂, H₂O, NO₂, NO, N₂O,CO₂, H₂O₂, HCOOH, CH₃COOH, (CH₃CO)₂O, or mixtures thereof, and thetin-containing material film is a tin oxide film.
 13. The method asclaimed in claim 12, wherein the tin oxide film includes a rutilecrystal phase.
 14. The method as claimed in claim 11, wherein: thereactant includes NH₃, a monoalkylamine, a dialkylamine, atrialkylamine, an organic amine compound, a hydrazine compound, ormixtures thereof, and the tin material film is a tin nitride film. 15.The method as claimed in claim 11, wherein the tin precursor compoundhas a substantially constant atomic layer deposition rate in atemperature range of about 270° C. to about 350° C.
 16. The method asclaimed in claim 11, wherein the tin precursor compound has asubstantially constant atomic layer deposition rate in a temperaturerange of about 270° C. to about 320° C.
 17. The method as claimed inclaim 11, wherein the tin-containing material film does not includehalogen elements.
 18. The method as claimed in claim 11, wherein formingthe monolayer of the tin precursor compound having the structurerepresented by Chemical Formula (I) on the substrate in the reactionspace includes supplying the tin precursor compound having the structurerepresented by Chemical Formula (I) onto the substrate for about 1second to about 100 seconds.
 19. The method as claimed in claim 11,wherein the tin-containing material film is a conductive barrier film, atunnel barrier film of a gate dielectric film, a barrier metal film forliquid crystals, a member for thin film solar cells, a member forsemiconductor equipment, or a nano-structure.
 20. A method ofsynthesizing a tin compound, the method comprising: obtaining SnX₂R₂ byreacting SnX₄ with SnR₄ according to Reaction Formula (I); and obtainingSn(NQ₂)₂R₂ by reacting SnX₂R₂ with LiNQ₂ according to Reaction Formula(II),SnX₄+SnR₄→SnX₂R₂  <Reaction Formula (I)>SnX₂R₂+2LiNQ₂→Sn(NQ₂)₂R₂+2LiX  <Reaction Formula (II)> wherein: Xincludes fluorine, chlorine, bromine, or iodine, and R and Q are eachindependently a C1 to C4 linear or branched alkyl group.
 21. The methodas claimed in claim 20, wherein X is chlorine, R is a methyl group, andQ is a methyl group, an ethyl group, or isopropyl group.
 22. The methodas claimed in claim 20, wherein: the reaction of Reaction Formula (I) isperformed at a temperature of about 0° C. to about 15° C., and thereaction of Reaction Formula (II) is performed at a temperature of about10° C. to about 50° C.
 23. A method of forming a tin-containing materialfilm, the method comprising: providing a substrate in a reactor;supplying a tin precursor to the substrate to form a monolayer of thetin precursor, the tin precursor being represented by Chemical Formula(I); supplying a reactant onto the monolayer to form the tin-containingmaterial film; and purging the reactor,

wherein, in Chemical Formula (I), R¹, R², Q¹, Q², Q³, and Q⁴ are eachindependently a C1 to C4 linear or branched alkyl group.
 24. The methodas claimed in claim 23, wherein: the reactant includes O₂, O₃, plasmaO₂, H₂O, NO₂, NO, N₂O, CO₂, H₂O₂, HCOOH, CH₃COOH, (CH₃CO)₂O, or mixturesthereof, and the tin-containing material film is a tin oxide film. 25.The method as claimed in claim 23, wherein: the reactant includes NH₃, amonoalkylamine, a dialkylamine, a trialkylamine, an organic aminecompound, a hydrazine compound, or mixtures thereof, and the tinmaterial film is a tin nitride film.
 26. The method as claimed in claim23, wherein the tin-containing material film does not include halogenelements.
 27. The method as claimed in claim 23, wherein the tinprecursor is supplied to the substrate for about 1 second to about 100seconds.
 28. The method as claimed in claim 23, wherein Q¹, Q², Q³, andQ⁴ are the same and are each a methyl group, an ethyl group, a n-propylgroup, or an isopropyl group.
 29. The method as claimed in claim 28,wherein R¹ and R² are the same and are each a methyl group, an ethylgroup, a n-propyl group, or an isopropyl group.
 30. A semiconductordevice including the tin-containing material film prepared by the methodas claimed in claim 23.